Slew rate of operational amplifiers is defined as the maximum rate of change of the output signal in response to changes in the large input signal. Ideally, the amplifier output under large signal conditions should follow the input signal. However, limitations on the slew rate cause the amplifier output response to be slower than the rate of change of the large input signal. The greater the slew rate the more closely the output signal follows the input signal. Various techniques have been developed to increase the slew rate of operational amplifiers. Examples of such techniques are described in U.S. Pat. No. 3,668,538 issued June 6, 1972, to Hearn and U.S. Pat. No. 3,688,208 issued Aug. 29, 1972, to Kandiah.